Honda's losing there prime....any ideas?

[mahi-madness]

Aloha all,

I am new to the forum, and i am thankful i found you guys cuz i cant figure out whats wrong with my engine. So here we go,

Running a 22' Corsair Foiler with twin Honda 90's on the back
Port motor has been losing its prime alot lately and going spongy during transit. Once i stop the motor to drift or to dive, when i go to fire again i have to pump the ball back up again. The starboard doesnt lose its prime nearly as quick but i always pump it up a bit whenever i go to do the jacked up one. Both motors have 300 hours on them, both motors have had carb jobs for running rough at idle. Again the port motor is rough at idle and needs another carb jobmad It seems like the jets get clogged if you look at them wrong. Anyhow, the other day i went diving....engines ran fine all the way out with the exception of that i pumped the ball for the port motor twice on the go.I did my dive and then went to fire the motor an hour later and it was running really rough. Figured it was starving for fuel so i started pumping the ball. It wouldnt pump up. I must have pumped the primer 100 times and nothing. I returned to port on the other engine. I was thinking that the fuel lines were old and possibly cracked or the fuel/water separator had a air bubble in it, or the ball was leaking. so,

first i cut all the tips on the hoses between the separator/fuel and the engine, and the ball in between. I checked the ball and it seems to be working. I filled the the fuel filters bowl, closed it back up and tried to get the prime going, but nothing. so i then opened the vent on the side and siphoned some gas into it from a one gallon can. i then pumped the ball and it got hard. i pulled the gas line, shut the vent, pumped the ball once for good measure and fired the motor and it ran like it normally does a bit rough at idle, strong when you give it gas. I ran it for ten minutes with some muffs on and then it ran very rough and died. I tried pumping the ball but it stayed spongy. basically the motor ran on the gas i injected into it but died once it was all consumed. My fuel gauge and my tach(both honda) went dead for this engine two weeks ago mysteriously. I am going to go put gas in it right now just to be sure but i seriously doubt this is it as there are preexisting nuances occurring (like the ball always going flat) before it died. I am thinking the fuel pump on the motor is failing our out, or the fuel water separator is faulty....any ideas??
i read some similar stories on this forum but the answers didnt seem applicable to my situation.

thanks in advance

 

[hondon]

Re: Honda's losing there prime....any ideas?

Are these engines operating from a shared fuel source?If so isolate the troublesome one by operating it on a portable fuel source to see if things change.When you mention the primer going flat do'es that mean it is imploding or just getting soft?Carb work on these units can be tricky in the hands of a rookie.